The Middle Ages designates the time span from the collapse of the Roman Empire to the Renaissance and Reformation, and the adjective "medieval" refers to whatever was made, written, or thought during the Middle Ages. The Middle Ages was a period of enormous historical, social, and linguistic change, despite the continuity of the Roman Catholic Church. In literary terms, the period can be divided into the Anglo-Saxon period (c. 450-1066), the Anglo-Norman period (1066- c. 1200), and the period of Middle English literature (thirteenth and fourteenth centuries).

Linguistic and cultural changes in Britain were accelerated by the Norman Conquest in 1066, when words from French began to enter the English vocabulary. Awareness of a uniquely English literature did not actually exist before the late fourteenth century. In this period English finally began to replace French as the language of government. Geoffrey Chaucer's decision to emulate French and Italian poetry in his own vernacular would greatly enhance the prestige of English as a vehicle for literature.

Britain was largely Christian during the Roman occupation. After the withdrawal of the Roman legions in the fifth century, three Germanic tribes invaded Britain: the Angles, the Saxons, and the Jutes. The conversion of these people to Christianity began in 597, with the arrival of St. Augustine of Canterbury. Bede's Ecclesiastical History of the English People (731) tells the story of the conversion. Before Christianity, there had been no books. Germanic heroic poetry continued to be performed orally in alliterative verse. Christian writers like the Beowulf poet looked back on their pagan ancestors with a mixture of admiration and sympathy.The world of Old English poetry is often elegiac.

The Normans, an Anglo-Saxon tribe of Germanic ancestry whose name is a contraction of "Norsemen," conquered England in the Battle of Hastings. Henry II, the first of England's Plantagenet kings, acquired vast provinces in southern France through his marriage to Eleanor of Aquitaine, the divorced wife of Louis VII of France. Fourlanguages co-existed in the realm of Anglo-Norman England. Latin remained the "international" language of learning, theology, science, and history. The Norman aristocracy spoke French, but intermarriage with native English nobility and everyday exchange between masters and servants encouraged bilingualism. Celtic languages were spoken in Ireland, Wales, Cornwall, and Brittany. Many literary texts written in Anglo-Norman England were adapted from French and Celtic sources. Romance, designating stories about love and adventure, was the principle narrative genre for late medieval readers. By the year 1200, both poetry and prose were being written for sophisticated and well-educated readers whose primary language was English.

Wars and plague devastated England in the fourteenth century, but these calamities did not stem the growth of trade or the power of the merchant class. The second half of the fourteenth century saw the flowering of Middle English literature in the writings of Geoffrey Chaucer, William Langland, and the Gawain poet. Chaucer drew from the work of illustrious medieval Italian writers such as Dante, Petrarch and Boccaccio, as well as ancient Roman poets. Chaucer had an ideal of great poetry, but he also viewed that ideal ironically and distanced himself from it. In the fifteenth century two religious women, Julian of Norwich and Margery Kempe, allow us to see the church and its doctrines from female points of view. Near the close of the period, Sir Thomas Malory gave the definitive form in English to the legend of King Arthur and his knights.